The present invention relates to image reading apparatuses, image forming apparatuses, methods of reading images, and recording media for reading original-document images and generating the image data of the original-document images.
It is known to prevent the printing of a copied image using an image forming apparatus, when a specific security pattern, such as a copy-forgery-inhibiting pattern, is included in the original-document image.
In the technique described above, the image of a single page of the original document is divided into a plurality of bands before being processed. To detect the security pattern at high speeds, detection of a security pattern is not performed for a band wherein the ratio of the number of blank pixels to the total number of pixels within the band is greater than or equal to a predetermined threshold. Although detection of a security pattern is not performed for bands including a large blank portion, it still takes a long time to detect a security pattern if there are few of such bands.